# Factorial definitions

Of a factor.

adjective

Of factors or factorials.

adjective

The product of a given series of consecutive whole numbers beginning with 1 and ending with the specified number.

The *factorial* of 5 (5!) is 1 × 2 × 3 × 4 × 5, or 120

noun

Of or relating to a factor or factorial.

adjective

The product of all the positive integers from 1 to a given number.

4 factorial, usually written 4!, is equal to 24 (1 × 2 × 3 × 4 = 24).

noun

The product of all of the positive integers from 1 to a given positive integer. It is written as the given integer followed by an exclamation point. For example, the factorial of 4 (written 4!) is 1 × 2 × 3 × 4, or 24.

(mathematics, combinatorics) The result of multiplying a given number of consecutive integers from 1 to the given number. In equations, it is symbolized by an exclamation mark (!). For example, 5! = 1 * 2 * 3 * 4 * 5 = 120.

noun